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Biomedical subjects

M Ohno

Publications and source records attributed to M Ohno.

At least 433 records · Page 24Linked to original sources
PubMed1990

[Cytomorphological reappraisal of choriocarcinoma cells--a proposal of a four cell pattern].

It is generally accepted that choriocarcinoma is composed of two cell types: syncytiotrophoblast (ST)-like cells and cytotrophoblast (CT)-like cells. In normal and molar pregnancy, there is another population of trophoblast in the cell column, the decidua and so forth. They are designated intermediate trophoblast (IT) and multinuclear IT. It remains to be clarified whether IT-like cells and multinuclear IT-like cells are observed in choriocarcinoma. In the present study, choriocarcinoma cells were reappraised cytomorphologically in three cases of uterine choriocarcinoma and additional three cases of metastatic choriocarcinoma. The results were as follows: 1. Choriocarcinoma cells could be classified into four cell types: ST-like cells, CT-like cells, IT-like cells and multinuclear IT-like cells. 2. IT-like cells predominated in metastatic lesions as compared with primary lesions. It seemed that choriocarcinoma shows both differentiations which take place in villous and extravillous trophoblasts of normal and molar pregnancy. IT-like cells were found to infiltrate into vessel walls, which, together with the predominance of IT-like cells in metastatic lesions, suggests that IT-like cells contribute greatly to the hematogenous metastasis in choriocarcinoma. The presence of ST-like cells, CT-like cells and multinuclear IT-like cells in metastatic lesions may indicate a germinative nature of IT-like cells.

Cell Nucleus↗
PubMed1989

[MR imaging of acute hemorrhagic brain infarction].

Six patients with acute hemorrhagic brain infarct were imaged using spin-echo (SE) pulse sequences on a 1.5 Tesla MR scanner. Including two patients with repeated MR imaging, a total of eight examinations, all performed within 15 days after stroke, were analyzed retrospectively. Four patients revealed massive hemorrhages in the basal ganglia or cerebellum and three cases demonstrated multiple linear hemorrhages in the cerebral cortex. On T1-weighted images, hemorrhages were either mildly or definitely hyperintense relative to gray matter, while varied from mildly hypointense to hyperintense on T2-weighted images. T1-weighted images were superior to T2-weighted images in detection of hemorrhage. CT failed to detect hemorrhages in two of five cases: indicative of MR superiority to CT in the diagnosis of acute hemorrhagic infarcts.

Acute Disease↗
PubMed1989

[MRI of middle cerebral artery occlusion].

Magnetic resonance imagings (MRIs) of ten patients with angiographically proved middle cerebral artery (MCA) occlusion were retrospectively reviewed. Eight of the ten patients had cerebral infarcts, one had an intraventricular hemorrhage, and the remaining one had no significant abnormalities. All patients were examined by the 1.5 Tesla SIGNA (GE), using spin-echo pulse sequences. In all patients, occluded MCA could be detected by MRI. All occluded arteries showed absence of flow void and were demonstrated as iso- or hyperintense structures relative to gray matter on T1-weighted images, iso- or hypointense on T2-weighted images. In eight of the ten patients, absence of flow void in the sylvian fissure was observed on T2-weighted images. Thus, MRI was proved to be a pertinent diagnostic modality for evaluating MCA occlusions.

Aged↗
PubMed1989

[MRI of internal carotid occlusion and high-grade carotid stenosis].

Magnetic resonance imaging (MRI) of twelve patients with angiographically proved internal carotid artery (ICA) occlusions and a patient with high-grade ICA stenosis was retrospectively reviewed. In one of the occluded ICA cases, the bilateral ICAs were involved. All patients were examined by a 1.5 Tesla system, using spin-echo pulse sequences. Both absence of normal flow void and decreased caliber of the cavernous portion of the ICA were detected in all patients. In ten of the thirteen occluded ICAs, flow void was completely absent. Most of the occluded arteries were isointense relative to gray matter on T1-weighted images, and were mildly hypointense on T2-weighted images. "Partial flow void" was observed in four cases, including the high-grade stenosis patient. So-called "border zone infarcts" were detected in seven patients (eight hemispheres). In three of the thirteen cases, however, cerebral infarcts relating to the ICA occlusions or high-grade stenosis were not observed. Since detection of abnormal ICA before cerebral infarct has occurred is extremely significant, we want to stress that abnormal ICA must be routinely searched for in the routine review of MRI of the head.

Aged↗
PubMed1989

[Acute hypertensive intracranial hemorrhage: MR imaging at 1.5T].

Twelve patients with acute hypertensive intracranial hemorrhage underwent magnetic resonance (MR) imaging within 7 days after the ictus. T1-weighted (TR = 400 msec; TE = 20 msec) and T2-weighted (TR = 2000 msec; TE = 80 msec) images were obtained on a 1.5 Tesla MR system. Signal intensities of hematomas were carefully evaluated and were compared with white matter intensity. A 9-hour-old hematoma was mildly hypointense on T1-weighted images, and was mildly hyperintense on T2-weighted images, suggesting a reflection of the high water content. On T2-weighted images, thin peripheral hypointense rim, probably due to deoxyhemoglobin, was also observed. Both of 15-hour-old hematoma and 21-hour-old hematoma had peripheral hypointensity on T2-weighted images. Both of 39-hour-old hematoma and 43-hour-old hematoma had central hyper-intensity on T1-weighted images and iso-to-mild central hypointensity on T2-weighted images, suggesting a reflection of decreased water content. A 3-day-old hematoma had thin peripheral iso-to-mild hyperintense rim on T1-weighted images, presumably due to intracellular methomoglobin. A 5-day-old hematoma had thin peripheral hyperintense rim on T2-weighted images, probably due to free methemoglobin. A 7-day-old hematoma was hyperintense on T1-weighted images and was mildly hypointense to hyperintense on T2-weighted images, presumably due to mixed intracellular methemoglobin and free methemoglobin.

Acute Disease↗
PubMed1989

Effect of S-adenosyl-L-methionine on impairment of working memory induced in rats by cerebral ischemia and scopolamine.

A repeated acquisition procedure in a 3-panel runway apparatus was used to investigate the effects to S-adenosyl-L-methionine (SAM) on impairment of working memory produced either by cerebral ischemia or by scopolamine in rats. Cerebral ischemia (2-10 min) produced duration-dependent increases in the number of errors (pushes made on the two incorrect panels located at each choice point) and increased latency (time before the rat reached the goal box). The increase in errors induced by a 5 or 10 min period of ischemia decreased gradually in subsequent training sessions, returning to the control levels in 6 days. The increases in both errors and latency induced by 5 min of ischemia were significantly reduced by 100 and 180 mg/kg SAM administered i.p. immediately after blood recirculation and 1 h before a test conducted 24 h after ischemia. SAM at doses up to 180 mg/kg nevertheless failed to reduce the increases in errors and latency if they were induced by 0.56 mg/kg of scopolamine. These results suggest that SAM has a beneficial effect on memory that has been impaired by cerebral ischemia.

Animals↗
PubMed1989

High-performance liquid chromatographic determination of substance P-like arginine-containing peptide in rat brain by on-line post-column fluorescence derivatization with benzoin.

A high-performance liquid chromatographic method with fluorescence detection is described for the determination of substance P, one of the neuropeptides, in the hypothalamus tissue of rat brain. The detection is based on on-line post-column fluorescence derivatization selective for arginine-containing peptides. The endogenous substance P-like arginine-containing peptide extracted from the tissue and [D-Phe11]-neurotensin as an internal standard were separated from various interfering substances on a reversed-phase column (TSKgel ODS-120T) by gradient elution with acetonitrile-phosphate buffer (pH 2.3). The peptides in the eluate were then automatically converted into fluorescent derivatives for detection by reaction with benzoin. Arginine-containing fragments produced by the enzyme reaction of substance P in the chromatographic fraction with trypsin were also detected, for the identification of the endogenous substance P-like arginine-containing peptide. The method was sensitive enough to permit the quantitative determination of the peptide at a concentration as low as 580 fmol/mg of protein in the brain homogenate. The concentration values of the substance P-like arginine-containing peptide in the tissue were 9.45 +/- 1.50 pmol/mg of protein (six determinations).

Animals↗
PubMed1989

Macrophage differentiation inducing factor from human monocytic cells is equivalent to murine leukemia inhibitory factor.

Human macrophage differentiation inducing factor (DIF) can induce differentiation of human myeloid leukemic cells into macrophage-like cells in vitro. A procedure is described for purification of DIF from serum-free human monocytic leukemia THP-1 cell-conditioned medium. The procedure included concentration of a conditioned medium by ultrafiltration, lentil lectin-Sepharose affinity chromatography, and fast protein liquid chromatography using Mono S and Mono Q. DIF-A of pI 9.0 and DIF-B of pI 8.8 were obtained after a final purification with a Mono Q column, and both DIF gave a single peak with a molecular weight of approximately 51,000 determined by gel chromatography. NH2-terminal amino acid analysis of DIF-A showed a noticeable homology with murine leukemia inhibitory factor. Human DIF-A was found to induce maturation of human and murine leukemic cells into both macrophage-like cells with nitro blue tetrazolium reducing activity and phagocytic cells, but was found to suppress proliferation of these leukemic cells.

Animals↗
PubMed1989

[Magnetic resonance imaging in lateral medullary (Wallenberg's) syndrome].

Eight patients with a clinical diagnosis of lateral medullary (Wallenberg's) syndrome were studied with magnetic resonance imaging (MRI) at 1.5 Tesla. On T1-weighted axial images, small hypointense lesion (infarct) was demonstrated in the region of lateral medulla in 6 patients. Ipsilateral hemiatrophy of the medulla was revealed in one patient. In the remaining one patient, a thrombosed vertebral artery was disclosed. It was therefore concluded that MRI is useful diagnostic modality for Wallenberg's syndrome.

Adult↗
PubMed1989

MR imaging of intracranial vertebral artery occlusion.

Magnetic resonance (MR) images of nine patients with intracranial vertebral artery occlusion (five proved, four presumed) have been reviewed. In two of nine, both vertebral arteries were occluded and in five of the nine, the basilar artery was also blocked. All occluded arteries showed absence of flow void and were clearly demonstrated as mildly hypo- approximately mildly hyperintense structures to brainstem parenchyma on the T1-weighted images. In two of five patients with basilar artery occlusion, retrograde filling of the distal basilar artery was detected. Thus, MR imaging, in particular the T1-weighted image, is a pertinent diagnostic modality for evaluating intracranial vertebral artery occlusion. Angiography does not seem to be required for confirmation.

Adult↗
PubMed1989

A neonatal case of apolipoprotein C-II deficiency.

A neonatal case of apo C-II deficiency with hypertriglyceridaemia and xanthomas is presented. The patient responded well to a special diet formula containing medium-chain triglycerides (MCT). This is the first case of apo C-II deficiency to be discovered during the neonatal period.

Apolipoproteins C↗
PubMed1989

Inhibitory effect of a selective kappa receptor agonist, U-50, 488H, on methamphetamine-elicited ipsilateral circling behavior in rats with unilateral nigral lesions.

The present study was designed to investigate the effect of U-50, 488H, a highly selective kappa opioid agonist, on ipsilateral and contralateral circling behavior induced by methamphetamine and by apomorphine, respectively. U-50, 488H (3.2-10 mg/kg IP) by itself failed to induce either ipsilateral or contralateral circling in rats with unilateral nigral lesions produced by an injection of 6-hydroxydopamine. U-50, 488H produced a significant dose-dependent inhibition of methamphetamine (1.0 mg/kg SC)-elicited ipsilateral circling. However, it had no effect on contralateral circling induced by apomorphine (0.5 mg/kg SC). The present results indicate that U-50, 488H presynaptically inhibits the release of dopamine in the rat striatum.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1989

CT of malignant mesenchymoma of the esophagus.

Malignant mesenchymoma rarely originates from the gastrointestinal tract. Here we describe a case of an esophageal origin in a 50-year-old man. Computed tomography contributed to the diagnosis by having shown unique ossifications in the tumor.

Esophageal Neoplasms↗
PubMed1989

Inhibition of mouse-killing behavior by S-adenosyl-L-methionine in midbrain raphe-lesioned and olfactory-bulbectomized rats.

The effect of S-adenosyl-L-methionine (SAM), a methyl donor, on mouse-killing behavior in rats with lesions of the midbrain raphe nuclei and in olfactory-bulbectomized rats was investigated. Systemic administration of SAM at doses of 180 and 320 mg/kg IP caused a significant inhibition of both kinds of mouse-killing behavior. The inhibitory effects of SAM on both types of mouse-killing behavior were almost equipotent. Microinjection of SAM at 10-100 micrograms/rat into the lateral ventricle also inhibited mouse-killing behavior induced by raphe lesions in a dose-dependent manner. The ED50 value of SAM for this effect was 38.6 (18.4-81.4) micrograms/rat. It is concluded that SAM has inhibitory effects on mouse-killing behavior in both raphe-lesioned and olfactory-bulbectomized rats through a site of action in the central nervous system.

Animals↗
PubMed1989

Simultaneous recording of tissue PCO2, interstitial pH and potassium activity in the rat cerebral cortex during anoxia and the subsequent recovery period.

Tissue PCO2 (carbon dioxide tension) (PtCO2), interstitial H+ (H+e) and potassium activities (K+e) were monitored in the cerebral cortex of rats during and after 2-3 min of anoxia. Anoxia was associated with systemic hypotension and caused H+e (extracellular hydrogen ion activity) to increase from pH approximately equal to 7.2 to pH approximately equal to 6.5, K+e to rise from approximately equal to 2.4 up to a maximum of approximately equal to 39 mmol/l, and PtCO2 to increase from approximately equal to 52 to approximately equal to 80 mmHg. Lactate increased from 2 to 5 mmol/kg tissue weight during anoxia and did not fall significantly after re-oxygenation for 10 min. A marked relationship existed between changes in PtCO2 and H+e. After re-oxygenation, K+e (extracellular potassium ion activity) and PtCO2 returned to the pre-anoxic level in a few minutes, whereas H+e took approximately equal to 30 min to recover. H+e recovered in a biphasic manner; a rapid decrease lasting approximately equal to 1 min preceded a much slower phase. We propose that the biphasic normalization of H+e after anoxia mainly reflects an initial and rapid washout of CO2 from brain tissue and a subsequent slow elimination of lactic acid occurring via metabolism and removal by the circulation.

Animals↗